System of electrical distribution.



No. 758,683. IATBIITEI) MAY 3,'1904.

' J. s. PEOK.

SYSTEM OF ELECTRICAL DISTRIBUTION.

APPLICATION FILED AUG. 8, 1903.

N0 MODEL. 2 SHEETS-SHEET 2.

Fig. 6.

2/ m 20 f I J3(/8 v3 654 2s r W/TNESSES: INVE/VTOR I I BY Patented Kay 304.

UNITED STATES PAT NT OFFICE.

JOHN s. PECK', or PITTSBURG, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A coaroaArlon or PENNSYLVANIA.

SYSTEM OF ELECTRICAL DISTRIBUTION.

SPECIFICATION forming part of "Letters Patent No. '7 58,683, dated May 3, 1904. Application filed Augnstd, 1903. Serial No- I68,744. (No model.)

To all whom it may concern:

Be it known that I, J OHN S. PnoK, a citizen of theUnited States, and a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Systemsof Electrical Distribution, of which the following is a specification.

' My invention relates to systems of elec- [O trical distribution, and particularly to such systems as involve the conversion of alternating currents into direct currents by means of rotary converters.

The object of my invention is to provide a method for so distributing the self-induction included in the alternating-current side of systems of electrical distribution employing rotary converters that equal difierences of potential may be obtained between slip-rings bev2o longing to the different phases.

In the accompanying drawings, Figure 1 is a diagram of a two-phase system of distribution embodying my invention. Fig. 2 is a diagram of the armature-windings of a twophase machine connected together at their middle points. Figs. 3 and 4 illustrate electromotive-force relations. diagrams of systems employing six-phase rotaries, the former being connected in double o delta and the latter in double star; and Fig. 7 is a diagram-showing the inductive resistances connected inside the double delta.

In the operation of rotary converters it is desirable to be able to vary, through a limited 3 5 range, the voltage delivered to the direct-current mains. Awell-known practiceis to place suitable reactance or self-induction in the alternating circuit supplying the rotary converters, so that if the fields of the rotary con- 4 verters are weakened lagging currents are set up, resulting in a lowering of the alternatingcurrent electromotive force supplied to the converters and a consequent lowering of the direct-current electromotive force delivered by the converters. If the converter-fields are strengthened, a raising of the direct-current electromotive force results. In a three-phase circuit supplying a converter a reactance-coil Figs. 5 and 6 are v conductors of the two phases,

would be employed in each of the three-phase mains. If the middle points of the two separate portions of the armature-winding ot' a two-phase rotary converter are not connected, it is only necessary series with one conductor of each of the phases; but if the middle points of the two portions of the winding are connected this arrangement would result in the impressing of unequal voltages on the various parts of tee said winding. For instance, in Fig. 3 the line A B represents in direction and magnitude one phase of the electromotive force impressed on the converter-armature winding and the line C D the other phase, the middle points of to place self-induction in i thewinding being connected as indicated at E in Fig. 2. If reactance is included in only 'one conductor of each phase and the field of the converter is strengthened, there results a raising of the alternating-current voltage inonly the two halves of the portion of the converter-armature winding which are connected directly to the conductors in which the selfinduction is included. These added voltages are represented by lines D Fand B G in Fig.

3, and it is evident that the resultant voltages between phases A F, F G, G C, and C A are unequal. The effect of the inequality of these voltages is to produce local currents in the rotary-converter armature-winding, causingundue heating. These difiiculties I avoid by providing self-induction inseries with both the efleet being to addequal small voltages to both portionsof the voltage impressed on each phase of the armature-winding or to subtract the same, as the case may be.

By referring to Fig. 4 it may be seen that the equal voltages represented by lines A H and B L and D K and GM are respectively added to each of the voltages represented by linesA B and O D and that the resultant V011 tages between phases HK, KL, LM, andMH are'equal. Only two reactance-coils, one per, phase, are required it they are made in halves, so that one-half. may be connected in series with each conductor of a phase.

In Fig. 1 the two-phase generator i is rep:

resented as supplying energy to the primary windings of two transformers 2 and 3, the secondary windings of which supply energy to a rotary converter 4. Reactance devices 5 are included in the alternating-current side of the system between the transformers 2 and 3 and the rotary converter 4 for the purpose of regulating the direct-current voltage supplied to the translating devices 6, hereinbefore set forth. The construction of said reactancecoils is evidently simplified by providing the two coils 7 and 8, pertaining to the respective phases, with a single magnetic circuit 9; but a different arrangement may be employed, if desired. The series field-magnet winding 10 of the rotary converter is connected so as to assist the effect of the shunt-winding 11, as is usual when inductive resistance is utilized in connection with rotary converters for regulating the direct-current electromotive force.

My invention may also be adapted for use with six-phase rotary converters, as shown in Figs. 5 and 6. As illustrated in Fig. 5, the two portions 12 and 13 of the secondaries of the three-phase transformer 14 are connected in a double-delta arrangement in order to obtain six-phase currents for the rotary converter t, thet'ransformer being supplied with energy from any suitable three-phase source. (Not shown.) The legs 15 of the iron core 16 of a three-phase reactance device 17 are severally provided with two coils 18 and 19, which are respectively connected in circuit between number of phases, reactance or inductive-resistance coils in series with each of said conductors, the rcactance-coils in series with conductors belonging to each phase being placed in the same magnetic circuit, a rotary converter having the middle points of the various portions of its armature-wimling connected together and having sluintand series fieldmagnet windings, and direct-current mains which supply suitable translating devices and which are connected to the commutator of the said rotary converter in the usual manner.

2." In asystem of electrical distribution. conductors for transmitting energy of an even number of phases, reactancc or inductive-rcsistance coils in series with each of said conthe secondary coils 12 and 13 and the rotary converter. Three single-phase reactancc devices may be employed instead of a single device, if desired, provided each device has two coils and the several coils are so connected in circuit as to provide the desired inductive resistance for each phase.

In Fig. and 21 of a three-phase transformer 22 connected in double star, and I have also shown two sets of translating devices 23 supplied by 6 l have shown the secondaries 2O a three'wire circuit the neutral conductor 24 z of which is connected to the neutral point of the secondary windings oi the transl'ormm' 22.

f rent mains which supply suitable translating In all other respects the combination is the same that shown in Fig. The combination shown in Fig. 1 might also be provided witha neutral conductor for three-wire distribution in the manner set forth in Patent No. 607,621, granted July 19, 1898, to the estinghouse Electric and .vlanut'acturing Company as assigncc of B. (i. Lamme. in either case my present invention serves to maintain stability both as .-':gards the electromotive forces of the different phases and as regards the neutral point of the system.

in Fig. 7 l have shown a combinatiorrthat is exactly like that shown in- Fig. '3, except that'thc coils l8 and if) of the reactance dcvicel7 are included in the double-delta circuits ol' the transl'ormer-windings l2 and 13 ll l l l l l ductors, a rotary converter having the middle points of the various portions of its armaturewinding connected together and having shunt. and series field-magnet windings, and directcurrent mains which supply suitable translating devices and which are connected to the commutator ot' the said rotary converter in the usual manner.

3. In a system of electrical distribution, conductors for transmitting energy of an even number of phases, rcactancc or intlucti vea'esistance coils in series with each of said conductors, the rcactance-coils in series with the conductors belonging to each phase being placed in the same magnetic circuit, a rotary converter having shuntand series field-magnet windings, and direct-current mains which supply suitable translating devices and which are connected to the commutator of the said rotary converter in the usual manner.

-4. In asystcm ot'clectrical distribution, conductors for transmitting energy of an even number of phases, reactance o1; inductive-resistance coils in series with each of said conductors, a rotary converter having shunt and series hold-magnet windings, and direct-curdcvices and which are connected to the commutator of the said rotary converter in the usual manner. i

In a system of electrical distrilmtion,con

doctors for transmitting energy ofan even number of phases, rcaetancc or inductive-resistance coils in series with each of said conductors, the rcactance-coils in series with the conductorskfi opposite phases being placed on the same portion of the magnetic circuit, a

assess 6. in a system of electrical distribution, transformers the secondaries of which are con nected in a double-delta arrangement, conductors for transmitting energy of an even number of phases, reactance or inductive-resistance coils in series with each of said conduc tors,'the reactance-coils in series with the conductors of opposite phases being placed on the same portion of the magnetic circuit, a rotary converter having shunt and series field-magnet windings, and direct-current mains which supply suitable translating devices and which are connected to the commutator of the said rotary converter in the usual manner.

-7. In a system of electrical distribution,

transformers the secondaries of which are con-- nccted in double-delta arrangement, conductors for transmitting energy of an even number of phases, reactance or inductive-resistance coils in series with each of said conductors, the reactance-coils in series with the conductors of opposite phases being placed on the same portion of the magnetic circuit, a rotary converter having shunt and series field-magnet windings and direct-current mains which 5 supply suitable translating devices and which are connected to the commutator of the said rotary converter in the usual manner.

8. in a system of electrical distribution transformers the secondaries of which are con- :3

nected in a double-delta arrangement and include inductive resistances within the delta,

the inductive-resistance coils in series with conductorsot' opposite phases being placed on the same portion of the magnetic circuit, con- 35 ductors for transmitting energy of an even number of phases, a rotary converterhaving shunt and series fieldanagnet windings and direct-current mains which supply suitable translating devices and which are connected 4 

